Questions:-

LSE - 03/2018

GENETICS

1. The gene sequence of a chromosome is HIJKL.MNOPQ .

What chromosome change resulted in the following sequences of the chromosome?

(a) HIJKNM.LOPQ

(b) HIJKL.MNONOPQ

 (c) HIJKLLK.MNOPQ

(d) HIJKL.MNCDEFG

1) Ans-.SEE THE STUDY MATERIAL.

2. The frequency of a recessive allele in a large randomly mating population is 0.2. What is the frequency of:

 (a) The dominant allele?

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 (b) The heterozygote?

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3. What roles do the following play in cloning a DNA fragment?

(a) Restriction enzymes.

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 (b) Vectors.

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(c) DNA ligase.

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(d) Electroporation.

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4. Compare and contrast the following terms:

(a) Gene and allele.

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 (b) Genotype and phenotype.

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(c) DNA and RNA.

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(d) DNA and chromosome.

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5. In water melon, red fruit colour (R) is dominant over cream fruit colour (r). A water melon plant homozygous for red fruits is crossed with a plant homozygous for cream fruits. The F1 are intercrossed to produce F2.

(a) Give the genotypes and phenotypes of the parents, the F1, and the F2.

 (b) Give the genotypes and phenotypes of the offspring of a backcross between the F1, and the red fruit colour homozygous parent.

 (c) Give the genotypes and phenotypes of a backcross between the F1, and the cream fruit colour homozygous parent

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6. Draw a short segment of a single polynucleotide strand, including at least three nucleotides. Indicate the polarity of the strand by identifying the 5´ end and the 3´ end. 10

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7. With the help of clear and labelled diagrams describe the composition and structure of the nucleosome. 10

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8. Describe the lac operon and how it controls the metabolism of lactose. Support your answer with clear and well labelled diagrams.

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9. Detail the various cell types of Immune System and their roles. 10

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10. Write short notes on:

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(b) Relation between genetics and intelligence.

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